Qfe & Qnh
I understand the differences between QFE & QNH but I don't understand how you convert heights between the two pressure scales, like this question:
Your aerodrome elevation is 24 ft, and the QFE you have just been given is 1021 millibars. What would you expect the aerodrome QNH to be?
A 1015 millibars
B 1020 millibars
C 1022 millibars
D 1027 millibars
There must be some mapping between the 2, but I just don't get it. Somehow I have to work out what the pressure difference is across 24ft and add it to 1021. Anyone ?